Closure operators | Group theory

Normal closure (group theory)

In group theory, the normal closure of a subset of a group is the smallest normal subgroup of containing (Wikipedia).

Video thumbnail

Difference Between Normalizer, Centralizer, and Stabilizer

An easy way to remember what is the normalizer and centralizer of a subgroup, and what is the stabilizer of an element under a group action. For people learning abstract algebra! Group Theory playlist: https://youtube.com/playlist?list=PLug5ZIRrShJHDvvls4OtoBHi6cNnTZ6a6 Subscribe to see

From playlist Group Theory

Video thumbnail

Group theory 31: Free groups

This lecture is part of an online math course on group theory. We review free abelian groups, then construct free (non-abelian) groups, and show that they are given by the set of reduced words, and as a bonus find that they are residually finite.

From playlist Group theory

Video thumbnail

Galois theory: Algebraic closure

This lecture is part of an online graduate course on Galois theory. We define the algebraic closure of a field as a sort of splitting field of all polynomials, and check that it is algebraically closed. We hen give a topological proof that the field C of complex numbers is algebraically

From playlist Galois theory

Video thumbnail

Definition of a group Lesson 24

In this video we take our first look at the definition of a group. It is basically a set of elements and the operation defined on them. If this set of elements and the operation defined on them obey the properties of closure and associativity, and if one of the elements is the identity el

From playlist Abstract algebra

Video thumbnail

Field Theory - Algebraically Closed Fields (part 2) - Lecture 10

In this video we should that algebraically closed fields exist and are unique. We assume that the direct limit construction works. The construction here depends on the axiom of choice.

From playlist Field Theory

Video thumbnail

Group theory 32: Subgroups of free groups

This lecture is part of an online mathematics course on group theory. We describe subgroups of free groups, show that they are free, calculate the number of generators, and give two examples.

From playlist Group theory

Video thumbnail

Commutative Algebra - Integral Closures - part 01 - Basics

This is a video for a second semester graduate algebra class.

From playlist Integral Closures

Video thumbnail

Group theory 21: Groups of order 24

This lecture is part of an online mathematics course on groups theory. It gives a survey of the groups of order 24, and discusses two of them (the symmetric group and the binary tetrahedral group) in more detail.

From playlist Group theory

Video thumbnail

Example of Group Action

Matrix Theory: Consider the set G of matrices of the form [x y \ 1 0] where x is nonzero real and y is real. Let G act on the real line R by [x y \ 1 0].t = xt + y. Show that G is a group, that the action is a group action, and that the action is faithful.

From playlist Matrix Theory

Video thumbnail

Anand Pillay 10/31/14 Part 1

Title: Interpretations and Differential Galois Extensions

From playlist Fall 2014

Video thumbnail

Richard Hain: Mixed motives associated to elliptic curves

Find this video and other talks given by worldwide mathematicians on CIRM's Audiovisual Mathematics Library: http://library.cirm-math.fr. And discover all its functionalities: - Chapter markers and keywords to watch the parts of your choice in the video - Videos enriched with abstracts, b

From playlist Algebraic and Complex Geometry

Video thumbnail

Galois theory: Normal extensions

This lecture is part of an online graduate course on Galois theory. We define normal extensions of fields by three equivalent conditions, and give some examples of normal and non-normal extensions. In particular we show that a normal extension of a normal extension need not be normal.

From playlist Galois theory

Video thumbnail

Samaria Montenegro, Universidad de Costa Rica

November 11, Samaria Montenegro, Universidad de Costa Rica Title: Groups definable in partial differential fields with an automorphism

From playlist Fall 2021 Online Kolchin Seminar in Differential Algebra

Video thumbnail

Reid Dale Talk 2 9/16/16 Part 1

Title: An Introduction to Pillay’s Differential Galois Theory (Part 2)

From playlist Fall 2016

Video thumbnail

Galois theory: Galois extensions

This lecture is part of an online graduate course on Galois theory. We define Galois extensions in 5 different ways, and show that 4 f these conditions are equivalent. (The 5th equivalence will be proved in a later lecture.) We use this to show that any finite group is the Galois group of

From playlist Galois theory

Video thumbnail

Kevin Buzzard (lecture 2/20) Automorphic Forms And The Langlands Program [2017]

Full course playlist: https://www.youtube.com/playlist?list=PLhsb6tmzSpiysoRR0bZozub-MM0k3mdFR http://wwwf.imperial.ac.uk/~buzzard/MSRI/ Summer Graduate School Automorphic Forms and the Langlands Program July 24, 2017 - August 04, 2017 Kevin Buzzard (Imperial College, London) https://w

From playlist MSRI Summer School: Automorphic Forms And The Langlands Program, by Kevin Buzzard [2017]

Video thumbnail

New isolated symplectic singularities with trivial fundamental group - Daniel Juteau

Workshop on Representation Theory and Geometry Topic: New isolated symplectic singularities with trivial fundamental group Speaker: Daniel Juteau Affiliation: CNRS, Université Paris Diderot; Member, School of Mathematics Date: March 31, 2021 For more video please visit http://video.ias.e

From playlist Mathematics

Video thumbnail

Galois theory: Separable extensions

This lecture is part of an online graduate course on Galois theory. We define separable algebraic extensions, and give some examples of separable and non-separable extensions. At the end we briefly discuss purely inseparable extensions.

From playlist Galois theory

Video thumbnail

Lie Groups and Lie Algebras: Lesson 43 Group Theory Review #2 (improved video quality)

Lie Groups and Lie Algebras: Lesson 43 Group Theory Review #2 In this lecture we examine a great way of becoming familiar with the smaller groups: the subgroup lattice. We use this to remind ourselves about normal subgroups, cyclic subgroups, and the center of a group. Errata!: The norma

From playlist Lie Groups and Lie Algebras

Video thumbnail

Polynomial Identity Testing via Optimization: algorithms by Rafael Oliveira

Discussion Meeting Workshop on Algebraic Complexity Theory  ORGANIZERS Prahladh Harsha, Ramprasad Saptharishi and Srikanth Srinivasan DATE & TIME 25 March 2019 to 29 March 2019 VENUE Madhava Lecture Hall, ICTS Bangalore Algebraic complexity aims at understanding the computationa

From playlist Workshop on Algebraic Complexity Theory 2019

Related pages

Empty set | Normal subgroup | Quotient group | Generating set of a group | Group theory | Conjugacy class | Presentation of a group | Free group | Subset | Group (mathematics)